Explosive cartridge unit



Dec. 26, 1950 B. COUNTERMAN 2,535,196

EXPLOSIVE CARTRIDGE UNIT Filed April 19, 1946 LEWIS Bv COUNTE RMAN INVENTOR.

BY EL A; Q. We

AGENT Patented Dec. 26, 1950 UNITED STATES PATENT OFFICE 2,535,196 nxrnosrvn CARTRIDGE UNIT Lewis B. Counterman, Kenvil, N. J., assignor to Hercules Powder Company, Wilmington, DeL, a corporation of Delaware Application April 19, 1946, Serial No. 663,297

'1 Claims.

This invention relates to explosive cartridges and, more particularly, to an explosive cartridge unit which is adaptable to use in the seismograph blasting art.

Heretofore in seismograph blasting two procedures have been followed. In accordance with one procedure, it has been customary to place in the drilled hole aplurality of explosive cartridges attached together in various ways as, for example, by attachment to a relatively long stick of wood. This method is tedious and timeconsuming, and

otherwise undesirable,

' -It has also been proposed to use an ammonium nitrate explosive in'a sheet metal cartridge, these cartridges being provided at their ends with threads so that the assembly can be made by interthreading a number of these cartridges. In order to explode the assembly thus produced, there is screw-threadedly attached at a point in the column a priming charge in the form of a special cartridge of trinitrotoluene or amatol (a mixture of trinitrotoluene and ammonium nitrate) which is provided with a blasting cap. This method is disadvantageous because the metal containers are expensive to manufacture and unduly increase the handling cost. Moreover, the use of a relatively heavy metal container undulylowers the percentageby weight of actual explosive. in the unit. In addition, the length ofthe metal cartridge shell is limited to about 8 inches because of manufacturing difilculties, whereas paper cartridges may be made in any length up to the maximum. allowed by I. C. C. shipping regulations. .In U. S. 2,317,415, there is disclosed the provision of a cartridge of explosive with a slidable frictionally held sleeve surrounding it, this sleeve being slidable along the cartridge into, corresponding frictional engagement with an adjacent cartridge placed in end-abutting relationship to the first-named cartridge. In this manner, a standard unit is provided which is readily built up by the operator into an explosive. column of any desired length. Difflculty arises in the use of telescoping cartridges of this type because ther is frequently a tendency for the adjacent cartridges to slip apart from one another as the column is lowered into a vertical borehole. V

. It is an object of the present invention to overcome this difliculty with the telescoping cartridges described in U. S. 2,317,415 while at the same time attaining all of the advantages of such telescoping cartridges over the prior art practices outlined briefly above.

Another object is to providea single cartridge unit which can be quickly associated with one or more units, identical therewith, to build up a seismograph blasting assembly of the desired length and explosive effect.

It is another object to provide an explosive cartridge unit useful in the seismograph blasting art which contains more explosive per unit of volume and more explosive per unit of weight than the metal assembly made as described above.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

These objects are obtained in accordance with the present invention of an explosive cartridge unit by providing for interlocking engagement between the connecting sleeve, which extends across the joint between adjacent cartridge units, and the cartridges themselves. It is preferred to provide circumferential abutments on the exterior near each end of the cartridge and on the interior wall near each end of the connecting sleeve. One end of the sleeve is preferably in locked telescoping assembly to the cartridge and the other end adaptable to being brought into locked engagement with a similar cartridge unit.

A preferred embodiment of this invention is 11- lustrated in the drawing wherein like numbers refer to like parts wherever they occur.

Fig. 1 is an isometric elevational view of the cartridge unit in partial section showing the preferred embodiment of the invention in a position preparatory to connection with a like cartridge unit, a portion of which is shown;

Fig. 2 is an isometric elevational view in partial section showing the invention of Fig. 1 in locked assembly to a like unit to form a columnary explosive assembly;

Fig. 3 is an isometric elevational view inpartial section of an alternative embodiment of the sleeve portion of the invention.

With reference to the drawings, an explosive cartridge I0, packed with explosive, may be of the usual tubular paper wrapped type. Slidably and telescopically mounted upon the cartridge Ill and in close fitting relationship thereto, is a connecting sleeve H.

A leading collar l2 and a retaining collar 13 formed on the cartridge Ill serve as abutment means for the slidable collar l4 formed on the connecting sleeve H and limit the axial movement of said sleeve.

Slots l5 permit sufiicient expansion of the open end of the connecting sleeve H and a locking collar it formed on the interior peripheral portion thereof to allow passage of the leading collar I! on an explosive cartridge l8 of a like unit sleeves mounted on the tubular sleeve and positionable over said slots.

'7. An explosive cartridge unit comprising a cylindrical explosive cartridge; a collar formed on the exterior peripheral portion near each end of said cartridge; a hollow cylindrical connecting sleeve; attachment means for slidable and telescopic attachment of the connecting sleeve to said cartridge, said attachment means comprising a raised member formed on the interior peripheral portion adjacent the end of the sleeve; and locking means disposed at the end of the sleeve opposite the attachment means for lockable attachment of said connecting sleeve to the cartridge of a similar explosive unit, said locking sleeve slidably mounted on the connecting sleeve and adapted to be positioned over said slots; and means mounted on the end of the connecting sleeve, whereby the movement of said sliding sleeve is limited.

LEWIS B. COUNTERMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,265,932 Maltby May 14, 1918 2,340,695 Rothrock Feb. 1, 1944 2,383,542 Godfrey Aug. 28, 1945 2,396,518 Martin Mar. 12, 1946 2,413,862 Cohan Jan. 7, 1947 2,415,422 Fogg Feb. 11, 1947 FOREIGN PATENTS Number Country Date 15,118 Great Britain of 1888 547,758 Great Britain Sept. 14, 1942 

